Methalologies will be further developed for determining the stereochemical courses of enzymatic reactions involving cleavage of bonds for phosphorus in biological phosphates. Stereochemical information is essential for the formulation of any detailed mechanism regarding the actions of nucleotidyltransferases, phosphotransferases, phosphatases, pyrophosphatases, and phosphodiesterases. The stereochemical courses of phosphoglucomutase, pyruvate dikinase, PEP synthase, NAD pyrophosphorylase, FAD pyrophosphorylase, nucleotide pryophosphatase, and protein kinases will be determined. These enzymes catalyze reactions that are generally recognized to be among the most important metabolic processes, and the stereochemical information sought here will be of essential importance to understanding how they work.